1. Field of Invention
The present invention relates to a printer that executes a printing process based on print data sent from a host computer, to a control method for a printer, and to an operation control program.
2. Description of Related Art
Retail stores are increasingly introducing POS systems in order to reduce the workload at the checkout register and to improve the accuracy of inventory management and purchasing management by linking product receiving, taking inventory, and sales results.
When the product barcode applied to a product being purchased is read at the POS register (POS terminal) installed at the checkout register of a retail store, the POS system records sales information for that product (such as the product name, quantity, sale price, total sale price, and time of sale) and issues a receipt recording the product sale price, for example.
Product sale information read by the POS terminal is normally sent from the POS terminal to a host computer, analyzed by the host computer, and used for inventory management and purchasing management.
The host computer that receives the product sale information from the POS terminal of the POS system generates receipt printing data arranged so that the sale information will fit within the specified width of the receipt paper, and outputs the resulting receipt printing data to the printer to issue a receipt.
Installed on the host computer are an application program for receipt printing that generates receipt printing data specifying the locations of the data contained in the sale information based on the product sale information received from the POS terminal, and a printer driver that outputs the receipt printing data generated by the application program to the printer.
The receipt printing data typically includes such data as the store name, the store location and phone number, the date and time of the sale, the names of the purchased products, the quantity sold, the sale price of each product, the total sale amount, and even sale announcements and other text data. The application program that generates the receipt printing data adjusts the format of the data in the receipt printing data appropriately to the data type.
In order to save paper, technology that improves the application program and printer driver installed on the host computer to generate reduced print data that shortens the line width by reducing the font size of the printed characters, for example, to enable printing on narrower paper has also been introduced. See, for example, Japanese Unexamined Patent Appl. Pub. JP-A-H05-24301, Japanese Unexamined Patent Appl. Pub. JP-A-H08-132703, Japanese Unexamined Patent Appl. Pub. JP-A-H09-286143, Japanese Unexamined Patent Appl. Pub. JP-A-2004-42406, and Japanese Unexamined Patent Appl. Pub. JP-A-2006-48520.
The paper width of the printing paper is typically fixed in printers that are used in conventional POS systems. This means that in order to change the receipt paper to paper with a narrower width in order to save paper, it is necessary to replace the printer itself with a printer that is compatible with the narrower paper. When the printer is replaced, the application program and printer driver installed on the host computer must also be changed so that the host computer can output receipt printing data compatible with the new paper width to the printer. This necessitates additional maintenance work to install the new program on the host computer.
Uniformly reducing the font size of the printed characters to produce reduced print data that fits within the changed paper width is relatively simple, but this can make the size of the characters printed on the receipt too small and reduce the legibility of the product names, purchased quantities, price, and other information printed on the receipt.